Currently it doesn't throw any more light on comparison as the author is asking for assistance in this task. However, they do put forward a few reasons why to choose OpenOffice.
MS Office has almost by default become the Industry Standard and in the days were you couldn't view or edit different document formats anyone who had to read .doc files could only do it with Word or had to send documents to business. Not the case any longer and with the move towards XML document format for standardisation there may well be some other small footprint solutions out there.
No problems with the Ads, I think. My firewall blocks ads as does firefox, so not many get through that lot, but the page appeared to display fine.